The same thing happens to any old house, not only soviet ones.
In my city most houses are close to 200 years old. That’s well before plumbing going into every flat, well before electricity and well before any of the other cool stuff like central heating, internet and so on.
Most of these houses don’t even retain the original apartment layout.
Houses are living things that see a lot of change when they get old enough.
Agreeing with you, just adding to it.
The same thing happens to any old house, not only soviet ones.
In my city most houses are close to 200 years old. That’s well before plumbing going into every flat, well before electricity and well before any of the other cool stuff like central heating, internet and so on.
Most of these houses don’t even retain the original apartment layout.
Houses are living things that see a lot of change when they get old enough.